Hitachi VM-H675LA Service Manual page 92

Pin I/O Active Abbreviation
No. Level
40 O (Pulse) XTAL OUT
12MHz
41 I (Pulse) EXTAL IN
12MHz
42 I (Pulse) CS-SYC(CAM)
43 I (Pulse) C-S DATA(CAM) For data communications with IC0201 (VIDEO DSP), IC1105 (EEPROM), IC1104
44 O (Pulse) S-C DATA(CAM) (DIGITAL µP) and IC1111 (D/A CONV.).
45 I (Pulse) C LOCK(CAM)
46 I 0V-3V OVER-C
47 I 0V-3V VCR KEYS2
48 I 0V-3V CHARGE_C
49 I 0V-3V BATTERY
50 ----- ----- GND
51 I ----- AVref
52 ----- ----- AVdd
53 I Hi/Lo CASETTE-SW
54 I 0V-3V +B_VDET
55 I Lo EXT_MIC
56 I 0V-3V VCR KEYS1
57 I 0V-3V TRACK ADJ.
58 I (Pulse) EST
59 I (Pulse) ESS
60 I (Pulse) ENV_DET
61 I (Pulse) RSS
62 I (Pulse) RST
63 ----- ----- GND
64 I (Pulse) C.SYNC
65 I (Pulse) TBC_CONT
66 ----- ----- GND
67 I (Pulse) DFG
68 I (Pulse) CFG
75 I (Pulse) CFG
69 O Hi LOAD
70 O Hi UNLOAD
71 O Hi CHARGE
72 O (Pulse) OSD_CS
73 O PWM D.SPEED
74 O PWM C.SPEED
76 I Lo V-DET[Lo]
77 I Hi DC900DET
78 O (Pulse) D. OUT
79 O (Pulse) CLOCK
80 O Hi T.FADE
81 I Hi/Lo BATT. SERIAL
82 ----- ----- ----------
Function
Drive X0901 to generate 12MHz main clock pulses.
Activates data communications with IC1104 (DIGITAL µP).
Overcurrent detection input during charging. Changes the gain during charging to
monitor the charge current.
VCR operation switch detection input (PLAY, DATE, TITLE and MUTE etc.).
Charge current detection input. Monitors the charge current during charging.
Input to detect the battery remaining level.
Grounded.
Reference voltage input. Connect to 3V line.
3V power input.
Erase prevention tab and Hi-8/Normal of the casette detection input.
Battery voltage detection input. Monitors the attached battery voltage.
External microphone connect detection input.
VCR operation switch detection input (REW, F.FWD and STOP).
For the connection of a tracking control for adjustment. When an ATF-R jig is
connected to PG0601 (test plug), the variable resistor on the ATF-R jig can be used
as a tracking control.
Take-up tape end detection input.
Supply tape end detection input.
Playback (PB) FM signal input.
Supply/take-up reel sensor inputs. Used to calculate the remaining tape and to
detect reel lock.
Grounded.
Composite sync signal input. The separated vertical sync signal is divided by
two to generate the 1/2V.SYNC pulse which is used to control the cylinder speed
during recording (reference signal).
Cylinder phase control signal input.
Grounded.
Cylinder FG (CYL. FG) pulse input. Controls the cylinder speed during recording
and playback.
Capstan FG (CAPST.FG) pulse input. Controls the capstan speed and used for
counting of the linear time counter and recording restart control (assemble
recording).
Loading motor drive outputs.
Charge circuit control output. Outputs "Hi" during charging to activate the charge
circuit.
Activates communications with IC0904 (CHARA. GEN.).
Cylinder servo control outputs.
Capstan servo control outputs.
Inputs whether a battery is attached or not. "Lo" is input when the battery is
detached, to shift the microprocessor to the backup mode in which the data is
saved.
Not used.
For data communications with IC0904 (CHARA. GEN.) and IC0401 (AUDIO
PROCESS (For stereo type)).
Rapid audio fading output. Outputs "Hi" when fading is started to fade the audio
signal in rapidly.
Battery serial time detection input.
Not used. Open.
6 - 57